feetupfun

There is a newly made instructional DVD for Twinshock and Classic trials bike riding available through Sammy Miller and probably other places too. Rider/instructor is Mick Andrews

Stator coils can be rewound by auto elec specialists Also consider possible loss of magnetism of the flywheel magnets

I have a set of M116 Alpina forks and yokes available but if you are the person who was asking about Matador forks last week and are located in the UK, I suspect the freight cost to you from Australia would be prohibitive

Ok I have had a look at photos of original Mk4 Matadors and the Matador triple clamps do look different to Sherpa T and Alpina models of the same era (that also have the tapered top end on the fork tubes). I don't have a good enough picture of Mk4 or Mk5 Pursang triple clamps to see how they compare with the MK4 Matador, but Pursang forks are in-line axle anyway. You can fit a later front end off an Alpina (M115/116, M137/138) but the top clamp will look non-standard (if that matters to you)

Soft drink (soda) bottles made for carbonated beverages are made from PET (not affected by petrol) and have an extremely high pressure rating. I've tested them with our petrol (pump gas) here and never had a problem with leakage or materials degradadation and they resist abrasion well too. I'm not saying they are suitable for all fuels though as I haven't tested anything other than our petrol in them. A few small bottles is probably safer than one big one and would fit better in a pack. Depending on what country you are in, they are probably not government-approved for carrying fuel. Toddlers accidentally drinking from the bottle is a potential hazard when reusing these bottles.

About pushing the dents out before welding on the inside - the dents in your photos should move back into position without further cracking and the reason you would do this is to preserve the external detail (logos and lines). If you are worried about the process, either do nothing or just weld the inside without pushing the dents out. It's your choice. I've got a clutch cover with bigger dents than yours on my M49 and it still holds the oil in and looks OK. I will not be doing anything unless it starts to leak. The material in those Bultaco casings is very good to work with compared with many other engine casings so if you give the casings to someone who is experienced at this sort of work you will have no problems.

For dents with internal cracking, push dents out from inside then weld repair on the inside

25kW is about what a high performance 250cc 4T or low performance 650cc 4T would produce

35mm leading axle Bultaco Betors and yes very likely that the forks and wheel and maybe triple clamps are shared with other Bultaos but before you go too far you should tell us which model Matador, not the year. Using a year for Bultacos is a bit rubbery for ID purposes. Look at the frame and motor ID numbers and the prefixes of these numbers will identify which model Matador you have.

NGK BP5ES

maybe cooling system problem - fan not running? radiator air path blocked? insufficient coolant quantity?

We are lucky here. The noise police haven't cottoned onto chainsaw racing yet so our racing chainsaws look like the one in the photo except there are no end mufflers on the chambers. The chainsaw racing is easily the most popular thing at our local (rural) show - all the bogans (me included) come out to watch Funny thing is the competitors have ear muffs and safety visors but the juiced-up spectators 10 feet away dont have to wear any PPE at all

yes you can change that seal without splitting the cases but my memory is a bit different to what Woody said. he may be right its a while now for me but my memory tells me that you will need to pull the clutch cover off and remove the clutch pressure plate to allow the actuating arm cam shaft to slide out.

What seal? What shaft? Sounds like you are asking about one of the crank seals or maybe even the seal behind the sprocket

http://www.southwestmontesa.com/ Jared Bates is your man

Q1 yes Q2 no

So you have written a reply to every posting you have read on these forums?

One leg has a spring, the other doesn't. One leg provides damping in one direction, the other, the other. All will be revealed when you pull them apart!

These will work but which one to use depends on circumstances Turn fuel tap off and put choke on - takes a while to work If it is in gear and you can get to the rear brake pedal, try stopping it with brake. Top gear works best if you can shift the gears. If you can flip it completely upside down without getting tangled in the chain or rear wheel, it will stop immediately with no further effort If you can do it without burning yourself, block the exhaust outlet. A bunched up cloth/shirt usually works well for this. So far I have stopped three runaway motors (Beta, Beta, Beta) by inverting the bike, another by using the rear brake (TY250Z) and another by blocking the exhaust outlet (Beta). A friend of mine suffered a piston/bore seizure using the turn-the-fuel-off-and-walk-to-a-safe-distance technique. Removing the plug cap will not stop a motor if the kill switch wont and is incredibly dangerous regarding risk of stopping your heart and breaking your arm Taking carby off will be effectively giving bike full throttle for brief period before it stops

A very reliable bike if maintained. The only weakness in the structural stakes I found was the rear subframe which was relatively easily bent in falls. I had mine straightened and rewelded twice while I had it (2 years). The main frame, swingarm and front end are incredibly strong and some would say overdesigned. The TY250Z does have limitations in some riding situations due to the long wheelbase and limited steering (side-to-side) angle.

I knew you would fined the answer here.

It is possible to avoid oily gunk depositing in the exhaust by running with very little oil in the fuel. Trouble is, it is not kind to the motor to run with so little oil. It will run fine but will wear out much faster than it would with adequate oil in the fuel. How little oil you mix with the fuel depends on what life you want to achieve from your motor. Because of this, you will find a variety of opinion about what is the ideal amount of oil to add. I use 40:1 semi-synthetic If your M198 has a standard exhaust and you burn out the gunk, the main (first) muffler section will need repacking to run properly. It will run but not very well without packing around the inner tube. To repack the main muffler it will need to be opened and there are many ways to do this.

Roger if you become a "Supporter"of this website you can post photos directly within your postings. Alternatively you can upload your photos to a photo hosting website and include a link to your photos in your postings. Regards David Lahey

The first TY250 twinshocks were made in 1973

The black goo on piston and throttle slide sounds like residue from incomplete combustion to me. If you clean it off the carby slide and it comes back with use, the piston rings are not sealing well. The lack of ring sealing may self-correct if you get the motor nice and hot in use. I have seen plenty of two stroke trials bikes that suffer from the rings being stuck in the grooves, which prevents them moving as required to seal against the bore. It usually happens on bikes that are only used gently and don't get hot enough to burn the goo out of the ring grooves (and other places). Riding up a long hill (a continuous minute or so at half to full throttle) should clean it out